Ovulation at cycle day 20


I don’t know why it happened but I always have a regular cycle and ovulation is always at day 12-14 ( I feel it usually I don’t test my self) but this month I felt cramps at day 20 so I bought a ovulation test and was Positive from November 2 Thursday till today November 5 ! So looks like my ovulation was late , and I think my periods are coming late too . We ate trying for a baby since August 2016 ! Does anyone have the same thing? Why happened